JPH01183866A - Atomic oscillator - Google Patents

Abstract

PURPOSE:To make it possible to perform lighting and maintenance of the lighting state at low exciting electric power, by separating a lighting starting electrode and the ground after the lighting of a light source lamp is started so as to suppress the spread of emitted light, and connecting the lighting starting electrode to the ground so as to light the lamp. CONSTITUTION:Light, which is emitted from a light source lamp 1, is detected with a photodetector 6. Its output is amplified in an amplifier 7 and added to a lighting control device 8. When the light is emitted from the light source lamp 1, the contact point of a switch 4 is 'opened' in the lighting control device 8. When the light is not emitted, the cycle of 'closing and opening' of the switch 4 is performed at least one time. Therefore, the spread of the emitted light with the lighting starting electrode 3 after the lighting is eliminated. The light can be emitted stably by the less amount of light. In this way, the lighting and the maintenance of the lighting can be performed with low exciting electric power.

Description

[Detailed Description of the Invention] [Summary] Regarding a method for maintaining lighting of a light source lamp of an atomic oscillator using an optical bombing method, the purpose is to maintain lighting of a light source lamp with lower excitation power, and the present invention includes a light source lamp, A lighting maintenance excitation coil, a lighting start electrode, a switch for connecting one end of the lighting start electrode to ground, a lamp exciter for supplying high frequency power to the lighting maintenance excitation coil, and a lamp exciter for supplying high frequency power to the lighting maintenance excitation coil; a photodetector for detecting; an amplifier for amplifying the output of the photodetector;
and a lighting controller that controls the switch using the output of the amplifier, and a cycle in which the contact of the switch is "open" when the light source lamp is lit, and the switch is "closed/opened" when the light source lamp is not lit. The lighting controller is configured to perform the following at least once.

[Industrial application field]

The present invention relates to a method for maintaining lighting of a light source lamp of an atomic oscillator using an optical bombing method.

An atomic oscillator is a type of oscillator that stably controls a crystal oscillator based on the quantum mechanical vibrations of atoms and molecules.It has particularly excellent long-term frequency stability and is used as a frequency standard. There are two types of atomic oscillators: active maser type ones and passive beam type ones.Among them, the passive gas cell type rubidium gas cell type atomic oscillator that uses the optical bombing method is relatively small. Because of this, it is widely used as a frequency standard for various devices.

In the above-mentioned atomic oscillator, a resonant cell filled with rubidium (Rb') is excited by light from a light source lamp, and at the same time it is irradiated with microwaves synthesized from a crystal oscillator, causing double resonance of microwaves and light waves. A control voltage is created based on the output resonance signal to control the crystal oscillator and obtain a stable oscillation frequency.

The light source lamps used in such atomic oscillators are generally excited with high frequency power of several tens to hundreds of MHz, but the difficulty of discharge light emission depends on the high frequency excitation power, especially when starting the discharge, and maintaining the discharge. This requires an excitation power several tens of times higher than when

However, the higher the excitation power, the worse the long-term stability and temperature characteristics of the atomic oscillator generally become.

For this reason, it is desirable for the light source lamp to be able to start lighting with low excitation power, and to maintain lighting at low excitation power even after it has been turned on.

[Conventional technology]

Conventionally used means for lighting and maintaining lighting of a light source lamp are disclosed in Japanese Patent Publication No. 59-17903, and an outline thereof will be explained with reference to FIGS. 3 and 4.

FIG. 3 shows a conventionally used rubidium gas cell type Atsuko oscillator. The atomic oscillator is an atomic resonator 21
The nuclear resonator 21 includes a light source lamp 1, an excitation coil 2 for maintaining lamp lighting, a lighting starting electrode 3, a lamp exciter 5, a light Detector 6, amplifier 7, reflector 9, filter cell lO1 resonance cell 11, cavity resonator 1
2, a multiplier 13, etc. Rh is sealed in the light source lamp 1, and when high frequency power is applied from the lamp exciter 5 to the excitation coil 2 for keeping the lamp lit, the light source lamp 1 emits light.

Unnecessary wavelength components of the light emitted from the light source lamp 1 are absorbed by the filter cell 10, and the light is incident on the resonance cell 11. Further, the output of the voltage controlled crystal oscillator 23 is multiplied by the frequency multiplier synthesizer 24 and the multiplier 13 to 6834.68-MHz, which is the resonance frequency of Rb f7, and is applied to the cavity resonator 12.

The microwave applied to the cavity resonator 12 causes the resonant cell l
When the resonant frequency of Rb gT in the resonant cell 11 coincides with the resonant frequency of the resonant cell 11, the light passing through the resonant cell 11 is absorbed most strongly due to optical microwave double resonance, and the output of the photodetector 6 decreases, and this decrease is identified by the amplifier 7. , Since the control signal for the voltage controlled crystal oscillator 23 is generated by the servo circuit 22 based on the output thereof, the oscillation frequency of the voltage controlled crystal oscillator 23 is controlled based on the extremely stable resonance frequency of Rb, and is accurate and It becomes highly stable.

Further, FIG. 4 shows the configuration of a light source lamp used in the conventional atomic oscillator shown in FIG. 3.

In the figure, 1 is a light source lamp, 2 is an excitation coil for maintaining lighting, 3
indicates the lighting start electrode. The lighting start electrode 3 is disposed on the outer periphery of the light source lamp 1 near the excitation coil 2 for maintaining lighting.
One end of it is connected to ground.

In the configuration of such a light source lamp, the lamp exciter 5
When high-frequency power required for maintaining discharge is applied to the lighting maintenance excitation coil 2 from the lighting starting electrode 3 connected to the ground,
A strong high-frequency electric field is generated between the excitation coil 2 and the lighting maintenance excitation coil 2, which spreads to other parts of the light source lamp 1 and lights up the entire light source lamp 1. After lighting, this state is maintained by high frequency power (magnetic field) supplied from the lamp exciter 5.

With such lighting and lighting maintenance means, it is not necessary to apply large electric power or high-pressure pulses when excitation of the gas in the light source lamp, and this contributes significantly to improving the lamp life and reducing the size of the lamp.

However, when the light source lamp is lit, a high-frequency electric field is always applied to the lighting starting electrode, so the amount of light is greater than when there is no lighting starting electrode, and there is still a need for improvement.

[Problem that the invention seeks to solve]

The conventional device has a problem in that the amount of light after the light source lamp is turned on is larger than that without a ground electrode. The reason for this is that connecting the lighting start electrode to the ground generates a high frequency electric field, which causes the plasma in the light emitting section to spread to the ground.

In the present invention, after the light source lamp starts lighting, the lighting start electrode and the ground are separated to suppress the spread of light emission, and if the light source lamp is not lit, the lighting start electrode is connected to the ground to turn on the light source lamp. This enables lighting and maintenance with low excitation power.

[Means for solving problems]

FIG. 1 is an explanatory diagram showing an example of the configuration of an atomic oscillator according to the present invention.

As shown in the figure, a light source lamp 1, an excitation coil 2 for maintaining lighting, a lighting starting electrode 3, a switch 4 that connects one end of the lighting starting electrode 3 to ground, and an excitation coil 2 for maintaining lighting. a lamp exciter 5 that supplies high-frequency power; a photodetector 6 that detects light emitted from the light source lamp 1; an amplifier 7 that amplifies the output of the photodetector;
and a lighting controller 8 that controls the switch 4 by the output of the light source lamp 1, and the lighting controller 8 opens the contacts of the switch 4 when the light source lamp 1 is lit, and closes the switch 4 when the light source lamp 1 is not lit. A "close/open" cycle is performed at least once.

[For production]

In the present invention, as shown in FIG. 1, light emitted from a light source lamp 1 is detected by a photodetector 6, and its output is amplified by an amplifier 7 and applied to a lighting controller 8.

The lighting controller 8 operates so that when the light source lamp is emitting light, the contact point of the switch 4 is "open", and when the light source lamp is not emitting light, the switch 4 is "closed/opened" in a small number of cycles (in both cases - times). As a result, after lighting, the light emission does not spread due to the lighting start electrode 3, and stable light emission is possible with a smaller amount of light.

〔Example〕

FIG. 2 shows an example of the configuration of an atomic oscillator according to the present invention, and shows a rubidium gas cell type atomic oscillator.

The atomic oscillator is composed of an atomic resonator 21, a servo circuit 22, a voltage-controlled crystal oscillator 23, and a frequency multiplier synthesizer 24. The atomic resonator 21 includes a light source lamp 1, an excitation coil 2 for maintaining lamp lighting, and a lighting starting electrode. 3, a switch 4, a lamp exciter 5, a photodetector 6, an amplifier 7, a lighting controller 8, a reflector 9, a filter cell 10, a resonance cell 11, a cavity resonator 12, a multiplier 13, etc. There is. Rh is sealed in the light source lamp 1, and when high frequency power is applied from the lamp exciter 5 to the excitation coil 2 for keeping the lamp lit, the light source lamp 1 emits light.

Unnecessary wavelength components of the light emitted from the light source lamp 1 are absorbed by the filter cell 10, and the light is incident on the resonance cell 11. Further, the output of the voltage controlled crystal oscillator 23 is multiplied by the frequency multiplier synthesizer 24 and the multiplier 13 to the resonance frequency of Rb gl, 6834.68 MHz, and is applied to the cavity resonator 12.

The microwave applied to the cavity resonator 12 causes the gas cell l
When the resonance frequency coincides with the resonance frequency of Rb 8'r in 1, the light passing through the resonant gas cell 11 is absorbed most strongly due to optical microwave double resonance, the output of the photodetector 6 decreases, and this decrease is reflected by the amplifier 7. Since the servo circuit 22 generates a signal to control the voltage-controlled crystal oscillator 23 based on the output, the oscillation frequency of the voltage-controlled crystal oscillator 23 is RbF.
The control is performed based on the extremely stable resonance frequency of t7, and is accurate and highly stable.

In the above operation, a part of the output of the amplifier 7 is applied to the lighting controller 8 to form a feedback circuit that controls whether the switch 4 is closed or opened.

Due to the configuration of this feedback circuit, when the light source lamp 1 is emitting light, the switch 4 is "open", and when no light is being emitted, the switch 4 is "closed/opened" at least once or more. is performed periodically.

In addition, this "close/open" operation when the lamp is not lit is easier to light the lamp than when the lighting start electrode is always connected to the ground because a rapidly changing voltage is applied. An atomic oscillator having a light source lamp that emits light with a correspondingly small excitation power is obtained.

〔Effect of the invention〕

As described above, according to the present invention, when the light source lamp is lit, no high-frequency electric field is applied to the lighting start electrode. Therefore, as in the past, it is possible to light up and maintain the lamp with lower excitation power than in the past.

Therefore, it is possible to improve the life of the lamp or to improve the stability of various frequencies due to an increase in the amount of light.
This is extremely effective in increasing the reliability of atomic oscillators.

[Brief explanation of the drawing]

Fig. 1 is a principle diagram showing the means for lighting and maintaining lighting of a light source lamp in the present invention; Fig. 2 is a block diagram showing an example of the configuration of the atomic oscillator of the present invention; Fig. 3 is an example of the configuration of a conventional atomic oscillator. 4 is a diagram showing a conventional light source lamp lighting and lighting maintenance means. In FIG. 1, l is a light source lamp, 2 is an excitation coil for lighting maintenance, 3 is a lighting start electrode, and 4 is a switch. contacts, 5 is a lamp exciter, 6 is a photodetector,

Claims (1)

[Claims] A light source lamp (1), an excitation coil (2) for maintaining lighting,
A lighting start electrode (3), a switch (4) that connects one end of the lighting start electrode (3) to ground, and a lamp exciter (4) that supplies high frequency power to the lighting maintenance excitation coil (2).
5), a photodetector (6) that detects the light emitted from the light source lamp (1), an amplifier (7) that amplifies the output of the photodetector (6), and a A lighting controller (8) that controls the switch (4), the contact of the switch (4) is set to "open" when the light source lamp (1) is lit, and the switch is closed when the light source lamp (1) is not lit. An atomic oscillator characterized in that (4) is a lighting controller (8) that performs a cycle of "closing and opening" at least once.